Optical pickup, and method and apparatus for correcting aberration of optical beam

(19)

(11)

EP 1 420 398 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	02.02.2005 Bulletin 2005/05

(43)	Date of publication A2:
	19.05.2004 Bulletin 2004/21

(21)	Application number: 03256785.1

(22)	Date of filing: 28.10.2003

(51)	International Patent Classification (IPC)⁷: G11B 7/135, G02B 27/00

(84)	Designated Contracting States:
	AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR
	Designated Extension States:
	AL LT LV MK

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Priority:

31.10.2002 JP 2002317987

(71)	Applicant: Pioneer Corporation
	Tokyo-to (JP)

(72)	Inventors:
	Kikuchi, Ikuya Tsurugashima-shi, Saitama-ken (JP) Ohtaki, Sakashi Tsurugashima-shi, Saitama-ken (JP)

(74)	Representative: Haley, Stephen
	Gill Jennings & Every, Broadgate House, 7 Eldon Street London EC2M 7LH London EC2M 7LH (GB)

(54)	Optical pickup, and method and apparatus for correcting aberration of optical beam

(57) A spherical aberration correcting unit (9, 11 to 13) corrects an aberration caused in an optical beam (B) radiated toward an information recording medium (DK) and focused on the medium. The correcting unit comprises an aberration corrector (9), driver (12), light receiver (11), and controller (13). The aberration corrector, which is composed of a plurality of optical members (9a, 9b), forms the optical beam into a parallel pencil and corrects the aberration caused in the optical beam. The driver drives any one of the optical members in an optical axis direction of the optical beam. The light receiver receives light reflected from the medium to produce a light-reception signal from the received light, and the controller controls the driver based on the produced light-reception signal.

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